No, I haven't used that setup. I prefer something that's effective on particles down to 0.1 micros to catch the different E.Coli (and other bacteria) better.

But I have made and used the gravity filtration setup based on the Aquamira Frontier Pro water straw and two Platypus hydration bladders. That setup is still in one of my bug-out bags but I don't rely on it as my primary filter anymore after discovering the filter is only effective to about 0.3 microns, which isn't tight enough to remove Salmonella and some of the more dangerous forms of E.Coli from the water.

I do like the ease-of-fill capability for the Platypus Big Zip bladders: You can unzip the entire top end of the bladder and scoop up 2 or 3 liters of water (depending on the size of the bladder you've got) at one sweep. They are also thin and roll-up tight into a small package. If you carry one Big Zip and one standard bladder, it's easy to identify which one is for dirty water and which for clean. My only concern is the thin material, while tough, is probably more susceptible to punctures or blow-out than the thicker material from Camelbak and others. Since I only used the Aquamira-based gravity filter a few times before back-burnering it, I can't tell you if this is a real-world concern or not.